Part 1

=UNIVERSITY OF CALIFORNIA PUBLICATIONS=

COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA

COMPARISON OF WOODS FOR BUTTER BOXES

By G. D. TURNBOW

BULLETIN No. 369 August, 1923

UNIVERSITY OF CALIFORNIA PRESS BERKELEY 1923

COMPARISON OF WOODS FOR BUTTER BOXES

G. D. TURNBOW

Butter boxes used in shipping and storing butter in California, are usually made of spruce which is largely shipped in from other states particularly from Washington and Oregon.

With the recent war, however, there came an acute shortage of spruce on the Pacific Coast with a corresponding increase in price. The commercial manufacturers did some work in an attempt to find a substitute for spruce, but the trade did not readily accept a change. There was a demand from both the lumber and the butter interests for investigation to find a suitable substitute for spruce.

The production of spruce is somewhat limited in California, but there is an abundance of white fir and a limited amount of cottonwood available. However, the creamerymen have not used white fir and cottonwood to any extent for butter containers, on account of the belief that these materials would impart a wood flavor to the butter.

Inasmuch as nearly all of the butter made in this State is shipped or stored in wooden containers, the use of white fir or cottonwood, would mean first, a material saving to the butter manufacturers in marketing expense, and second, an opportunity for the lumber interests to use a large amount of raw material already available in California, which heretofore had been of little commercial value or use.

BUTTER ABSORBS ODOR

The volatile fats in butter have the property of absorbing odors, which often results in an undesirable flavor. Great care then must be exercised in keeping butter from coming in contact with materials that will impart a foreign flavor. Butter need be exposed to foreign odors only a short length of time before the flavor is permanently affected.

Experiments were conducted, therefore, to determine whether white fir or cottonwood would impart a flavor to the butter and also to determine the possibility of storing butter in cubes and marketing it in 60-pound cases when these woods were used.

This experiment was suggested by Mr. M. B. Pratt, Deputy State Forester. Through his coöperation, all box material was furnished by the Swayne Lumber Company of Oroville and the Capitol Box Factory of Sacramento.

CUBE BUTTER IN COLD STORAGE

The butter for cold storage was packed in white fir, cottonwood, and spruce containers holding ten pounds each. Both seasoned and unseasoned woods were used in each of the three methods of packing.

The first set packed with butter were plain unseasoned boxes of each of the woods. The second set had the inner surface paraffined before packing. The method of paraffining was to invert the box over a steam jet and steam thoroughly. This served a double purpose in that it opened the pores of the wood and allowed the paraffin to penetrate, and the heated surface of the wood kept the paraffin in a liquid condition so that it could be put on in a thinner coat than if the paraffin had been applied to a cold surface. After the boxes had been allowed to drain, the inside was then painted with paraffin at 240° F. This method gave a complete covering to the wood, a result which is not always obtained by some of the commercial paraffin atomizers. The third set was paraffined as above and, in addition, lined with good parchment paper so that no butter could come in contact with either wood or paraffin (fig. 1). Twenty-three 10-pound boxes were packed in the three ways.

They were filled with the butter from one churning which scored 92½ after being chilled for 24 hours at 50° F. and were shipped immediately after the first scoring to a cold storage plant in San Francisco and stored at a temperature of 12° F. The butter was scored monthly for six months. The summary of the scoring is given in table 1.

TABLE 1

Influence of Various Woods on Cube Butter in Storage

This scoring was done by T. J. Harris, San Francisco Dairy Produce Exchange, S. L. Denning, Oakland, and G. D. Turnbow, College of Agriculture, University of California.

========================================================================= Average score No. Kind of butter in of of How First Lowest Average of same kind sample wood treated score score all scores of box ------------------------------------------------------------------------- 1 White Fir Unseasoned 92.5 89 90.857 No Paraffin No Parchment 2 Cottonwood Unseasoned 92.5 86 89.214 No Paraffin No Parchment 3 Spruce Unseasoned 92.5 88 90.785 No Paraffin No Parchment 4 Spruce Seasoned 92.5 89 90.642 Paraffin No Parchment 6 White Fir Seasoned 92.5 90 90.857 Paraffin No Parchment 7 Cottonwood Seasoned 92.5 87 89.571 Paraffin No Parchment ------------------------------------------------------------------------- 5 Cottonwood Unseasoned 92.5 88 89.857 Paraffin No Parchment 8 Spruce Unseasoned 92.5 90 90.928 Paraffin No Parchment 9 White Fir Unseasoned 92.5 89 90.571 Paraffin No Parchment ------------------------------------------------------------------------- 10 Cottonwood Unseasoned 92.5 91.0 91.714 Paraffin Parchment 11 Cottonwood Unseasoned 92.5 89.0 90.571 91.142 Paraffin Parchment 18 Cottonwood Unseasoned 92.5 89.0 91.142 Paraffin Parchment ------------------------------------------------------------------------- 12 Spruce Unseasoned 92.5 90.5 91.5 Paraffin Parchment 13 Spruce Unseasoned 92.5 91.0 91.571 91.333 Paraffin Parchment 14 Spruce Unseasoned 92.5 90.0 90.928 Paraffin Parchment ------------------------------------------------------------------------- 15 White Fir Unseasoned 92.5 89.0 90.928 Paraffin Parchment 16 White Fir Unseasoned 92.5 90.0 91.285 91.107 ------------------------------------------------------------------------- 17 White Fir Seasoned 92.5 89.0 90.857 91.142 Paraffin Parchment 20 White Fir Seasoned 92.5 90.5 91.428 Paraffin Parchment ------------------------------------------------------------------------- 19 Cottonwood Seasoned 92.5 90.5 91.571 Paraffin Parchment ------------------------------------------------------------------------- 21 Spruce Seasoned 92.5 90.0 91.214 Paraffin Parchment 22 Spruce Seasoned 92.5 90.0 91.571 91.523 Paraffin Parchment 23 Spruce Seasoned 92.5 91.0 91.785 Paraffin Parchment -------------------------------------------------------------------------

SIXTY-POUND BOXES PACKED FOR MARKET The butter for market was cut into two-pound squares, wrapped and packed in 60-pound containers, made of white fir, cottonwood and spruce (figs. 2, 3 and 4). The butter was stored in a cold room, the temperature of which ranged from 48° to 50° F. It was held in storage twenty-eight days, which is within two days of the maximum time butter may be held and still sold as fresh butter. Butter held over thirty days must be labeled “storage butter.” The butter was scored four times during the storage period. The butter used was all from the same churning which scored 93 after being chilled for twenty-four hours at 50° F.

Table 2 gives a summary of the scores showing the effect upon butter in containers with varying treatments. When paraffined, the inside of the boxes was painted with the paraffin at 240° F.

TABLE 2

Influence of Various Woods on Butter Packed in 60-Lb. Boxes